Lubricating greases



Patented May 8, 1945 LUBRICATING GREASES John D. Morgan, South Orange,and Russell E. Lowe, East Orange, N. J., assignors to Cities Service OilCompany, New York, N. Y., a. corporation of Pennsylvania No Drawing.Application August 10, 1943,

' I Serial No. 498,082

This invention relates to greases. More par- ,ticularly the inventionrelates to greaseshaving a substantially uniform viscosity .at theusualworking temperatures.

For the operation of gun turrets it is important that the lubricant,which is a grease, shall have a substantially uniform viscositythroughout the temperature range of the parts on which it is used. Therollers and pinions ot' a gun turret usually operate in the temperaturerange of 35 to 80 F. It is important also that the grease. shall adhereto the parts and shall have a uniform consistency in the temperaturerange of use.

The primary object of the present invention is to provide a grease whichwill cling to the parts 'to be lubricated and will have a comparativelyuniform viscosity in the temperature range of 35 to 80 F. I

Another object of the invention is to provide a grease which will benon-corrosive'to steel pinions and rollers as well as copper parts.

The United States Navy places a very rigid specification on greaseswhich are to be used on gun turrets because these turrets must operateproperly under very severe operating conditions. The specificationrequires a uniform consistency with a dropping point of 250 F. minimum,a work penetration of 330 to 350 at 77 F. and a V work penetration of280 minimum at 40 F. This.

lubricant shall be only slightly corrosive to copper and non-corrosiveon steel. Furthermore the grease must cling to the steel parts on whichit is applied.

A grease which will meet these specifications has been found to have thefollowing composition:

l Percent by weight Calcium stearate 7 Lithium stearate 2. Aluminumtri-stearate 0.6- Lead oleate 1 Mid-Continent pale oil 67 Naphthenic oil'22.4-

Consistency Homogeneous Dropping point"-.. EL- 254, Work penetration-at77 F 338 Work penetration at 40" F 320- Adhesion to steel.. CompleteCorrosion to copper None Corrosion to steel None 4 Claims. (01. ass-3.6

is added to the mixture and thoroughly blended therewith. Thereafter themixture is constantly agitated while being heated, to a maximum of 420F. Foaming of the mixture starts at 250 F. and the foam breaks at about390 F. The -vol-. ume of foam is about equal to the volume of liquid.The mixture. of foam and liquid is then rapidly chilled to form thegrease.

The chillin is preferably accomplished by passing it over a chillingroll or placing it in layers in shallow pans, the layer beingapproximately one-sixteenth of an inch thick. l j

The Mid-Continent neutral oil is preferably an oil of #3' color andhaving a viscosity of 400 at F. The'naphthenic oil is a pale oil havinga vicosity of 1200 at 100 F. I

The calcium stearate and lead oleate have the effect of making thegrease soft. The aluminum stearate is very effective inmaking a uniformblend of the soaps in the oils and prevents the mixture from breaking.The lead oleate acts effectively also as a corrosion inhibitor to.prevent the grease from corroding either copper or steel parts.

A'grease manufactured in accordance with the above process when theingredients are used in the roportions mentioned above, hassubstantially the following specification:

The specification which has been set by the Navy is quite rigid in orderto have the grease maintain a substantially uniform viscosity throughoutthe working range and also provide a grease which will cling to thesteel and not drop from the parts being lubricated while the turret isin operation.

The preferred form of the invention having been thus described what isclaimed as new is:

1. A turret lubricating grease, comprising about 7% by weight of calciumstearate, about 2% by weight of lithium stearate, about 0.6% by weight 4of aluminum stearate, about 1% by weight of lead oleate, the remainderof the lubricant consisting essentially of a mixture of neutral mineraloil and naphthenic oil, said grease being prepared by mixing thestearates withtheoils thenadding the lead oleate, heating the mixture toa maxi-' mum temperature of about 420 F., and then' rapidly chilling themixture.

2. A turret lubricating grease, comprising about 7% by weight oi calciumstearate, about 2% by weight of lithium stearate, about 0.6% by weightof aluminum tristearate, about 1% by weight of Y Y lead oleate, theremainder of the lubricant con sisting essentially of a mixture ofneutral mineral 1 oil and a pale oil in the ratio of about 3 to 1,

said grease being prepared by mixing the stea-.

rates with the oils then adding the lead oleate, heating the mixture toa maximum temperature of about 420 F.', and then rapidly chilling themixture to produce the grease.

3. A turret lubricating grease, comprising about 67% by weight of aneutral mineral oil having a viscosity of about 400 at 100 F. about22.4% by weight of a pale mineral oil having a viscosity of about 1200at 100 F., about 7% by weight of calcium stearate, about 2% by weight oflithium j bricating grease, which comprises mix'ing about 67 by weightof a neutral mineral oil with about stearate, about 0.6% by weight ofaluminum stearate, and about 1% by weight of lead oleate.v

4. The method of manufacturing a turret lu- 22.4% by weight of a palenaphthenic oil, intimately mixing with this oil mixture about 7% byweight of calcium stearate, about 2% by weight "of lithiumstearate, andabout 0.6% by weight of aluminum stearate, thereafter incorporating inthe resulting mixture about 1% by weight of 1 lead 0leate, heating thefinal mixture to a maximum temperatureof about 420 F., and rapidlychilling the heated mixture to produce the desired grease.

' JOHN D. MORGAN. RUSSELL E. LOWE

